I want to base my embedded project on FreeRTOS, modify the original source code of FreeRTOS (strip some functionality, remove some unused code, increase reliability), write my application specific code and then I want to sell the whole product and give warranty for it.

MIT license for FreeRTOS have disclaimers like: "THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND...". As far as I know I am required to include the MIT license text in my product even when I do not disclose the source code (e.x. in documentation or somewhere like the "About" tab).

So what is the impact of the MIT license terms of FreeRTOS on my final product warranty? Am I allowed to give warranty for my product? (I will modify the original FreeRTOS source code, improve reliability, test and verify it in my application)

There is something like OpenRTOS or even pre-certified SafeRTOS that are targeted specifically for commercial use, but I am not sure if this is the only way for me to be able to provide warranty for my product to my customers and/or apply for some industrial certification in the future.